The judge told Holmes that he was being held on suspicion of first-degree murder charges after Friday's shooting spreeat a movie theater in suburban Denver, which claimed the lives of 12 people and injured 58 others.

When asked if he had anything to say, he did not respond, allowing his lawyer to speak on his behalf.

Authorities said the 24-year-old former grad student is refusing to cooperate and it could take months to learn what prompted the horrific attack on moviegoers at a midnight screening of the latest Batman film.

Investigators said they found a Batman mask inside Holmes' booby-trapped apartment after the attack.

Holmes has been held in solitary confinement at the Arapahoe County Jailsince Friday.

Eighteenth Judicial District Attorney says her office is considering pursuing the death penalty against Holmes.

Monday afternoon, a lawyer representing some of Holmes' family said their hearts go out to the shooting victims and their families. Lawyer Lisa Damiani met with lawyers in San Diego. she refused to answer questions about Holmes and his relationship to the family.

Authorities released a booking photo of Holmes Monday afternoon. In the mugshot, Holmes had a wide-eyed stare similar to the look in his first court appearance Monday morning.